Automatic riveting machine



Sept. 17, 1957 P. NEMITZ 2,806,391

AUTOMATIC RIVETING MACHINE Original Filed April 23, 1952 I Pug/B76177;

Arr/5.

2,806,391 Patented Sept. 17, 1957 AUTOMATIC RIVETIN G MACHINE Paul Nemitz, Stuttgart-Zuiienhausen, Germany 4 Claims. (Cl. 7846) This invention relates to automatic riveting machines and is a division of applicants original specification filed April 23, 1952, bearing Serial No. 283,866, now abandoned, the present division relating particularly to electronic means for controlling the anvil member of such an automatic riveting machine.

One important object of the invention is to provide novel electronic means controlled by the passage of a. rivet to ward the riveting position, such means automatically moving the anvil of such a riveting machine into and out of riveting position.

Another object of the invention is to provide a device of the above described character wherein closing of a circuit through the anvil control device is controlled in part by cam means so that the anvil control may be caused to operate in timed relation to a riveting plunger or head.

A still further important object of the invention is to provide a device of this character wherein both a cam means as just described and the passage of a rivet act in combination to control the anvil operating circuit.

With the above and other objects in view, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly claimed.

In the drawing:

Fig. l is a diagrammatic view showing the electronic circuit means for controlling the anvil of an automatic riveting machine.

Fig. 2 is a diagrammatic view showing the arrangement for moving the anvil into and out of riveting position, and

Fig. 3 is a fragmentary sectional detail of a part of the guide means for the rivets of the automatic riveting machine.

As disclosed in the accompanying drawings, there is shown in Fig. 3, a part of the guide means for rivets of an automatic riveting machine which has an inclined chute 41 down which are fed rivets 44. In this chute adjacent its lower end there is provided a stop pin 41*, the operation of which is effected by mechanical means from the body of the machine at properly spaced intervals. Extending downwardly from the lower end of the chute 41 is a chute 45 which leads to a delivery nozzle 46. At the top of the chute 45 is a pair of spaced contacts 42 and 43, the spacing of these contacts being such that when a rivet 44 passes between them current will flow from one contact to the other through the rivet.

As shown in Fig. 1, conventional A. C. power supply lines S connect to the primary winding T of a transformer having a secondary winding T From one terminal of the secondary winding T extends a conductor 51, which leads to the contact 42 and from the contact 43 extends a conductor 49 which leads to a contact 52 fixed in spaced relation to a contact 53. The space between the contacts 52 and 53 is arranged to be bridged by a movable contact carried by a rod 55, the lower end of which rests on the periphery of a cam 50. This cam will be, in actual practice, connected to the operatingrmechanism of the automatic riveter. From the contact 53 a conductor 56 leads back to the conductor 51. From the remaining terminal of the transformer secondary T there extends a conductor 75 which leads to one terminal of the winding of an electro-magnet M, the other terminal of which is connected by a conductor 62'to one terminal 58 of a rectifier R having its other terminal 59 connected by a conductor 60 to the conductor 49 and thus to the contact 43 In the operation. of the device as so far described, it is to be understood that the cam 50 is constantly cyclically revolving and that the rivets 44 are successively fed between the contacts 42 and 43. Under these circumstances,

, when a rivet 44 closes the circuit between contacts 42 and 43 current will flow from the secondary T through conductor51 to the contact 42, through the rivet 44, to

contact 43, and through conductor 49 to close the circuit for operating the electro-magnet M from the transformer secondary. Normally, during other portions of the cycle, this circuit is closed by the parallel closing circuit of contact 54, when the rod is lowered off the lobe on the cam 50. The lobe raises rod 55 during the portion of the cycle when the next rivet is properly fed through between the contacts 42 and 43. Thus, if the rivet feed should be interrupted and no rivet closes contacts 42 and 43 at this time in the cycle, the circuit is broken and the anvil is caused to recede from its elevated operative position to prevent injury to the work. By this arrangement the cam actuated circuit closer and the rivet actuated circuit closer are connected in parallel. In order to manually render ineffective these parallel portions of the circuit just described the conductors and 51 are bridged as at 61 by a manually operable switch k being inserted in the bridging.

In Fig. 2 there is illustrated the anvil 63 of the riveter, this anvil operating in a guide 64. At the lower end of the guide there is provided a support 65 whereto is pivoted the lower end of a lever 66, the upper end of which is pivotally connected to the lower end of a lever 67 having its upper end pivoted to the bottom of the anvil 63. Extending laterally from the joint connecting the levers 66 and 67 is a connecting rod 69 which is carried by a piston 70 operating in a hydraulic cylinder 71 pivotally mounted at 71'. This hydraulic cylinder has inlet and outlet pipes 72 and 73 controlled by 4-way valve means 74 actuated by the magnet M.

The magnet M is only energized to straighten the elbow joint formed by the levers 66 and 67 upon the circuit being closed through a rivet 44 and/ or the movable contact 54, or by manually operable switch It,. When the magnet is deenergized, the piston 74) will move to the right of the cylinder 71 and the elbow joint will be flexed so that the anvil 63 will drop downwardly and thus be out of position to support a rivet against the action of the riveting ram.

What is claimed as new, is:

1. In an electronic control for automatic riveting machines having a circuit controlled means for maintaining its anvil in raised operative position, a circuit closer for said circuit consisting of a pair of contacts adapted to be bridged by a rivet passing between said contacts, a second parallel circuit closer including a movable contact, a cam actuating said movable contact to cyclicallly close and open the second circuit closer during the operation of the machine, and conductive means connected to said circuit in parallel with said closers for manual operation into closed or open position.

2. In an electronic control for automatic riveting machines having a circuit controlled means for maintaining its anvil in raised operative position, a circuit closer for said circuit consisting of a pair of contacts adapted to be bridged byv a rivet passing between said-contacts, a second parallel circuit closer including a movable contact, a cam actuating said movable contact to cyclically close and open the second circuit closerduring the operation of the machine, conductive meansconnected to said circuit in parallelwith said closers, and a manually controlled cutout bridge bridging said conductive means and thus upon closing of the bridge rendering the closing action of said circuit closers ineffective.

3. In an electronic control for automatic riveting ma chineshavingta reciprocable anvil and a circuit for controlling its movement into raised operative position, a circuit closer for said circuit consisting of a pair of contacts adapted to be bridged by a rivet passing between said contacts, a second parallel circuit closer including a movable contact, a cam actuating said movable contact to cyclically close and open the second circuit closer during operation of a said machine, and conductive means connected to said circuiticlosers in parallel with said closers for manually closing said circuit; in combination with said reciprocable riveting machine anvil, fluid pressure actuating means eifecting reciprocation of the anvil into raised operative position, electro-magnetic means controlling the action of the last mentioned means, and conductive connections connecting said electro-rnagnetic means in the circuit closed by said parallel circuit closers.

4. In an electronic control for automatic riveting machines having a reciprooable anvil and a circuit for controlling its movement into raised operative position, a circuit closer for said circuit consisting of a pair of contacts adapted to be bridged by a rivet passing between said contacts,- a second circuit closer including a movable contact, a cam actuating said movable contact, to close and open the second circuit closer, conductive means connecting said circuit closers in parallel in said' circuit, and a manually controlled cut-out bridge bridging said conductive means and thus upon closing of the bridge rendering the closing action of said circuitclosers superfluous; in combination with said reciprocable riveting machine anvil, fluid pressure actuating means effecting reciprocation of the anvil, electro-magnetic means controlling the action of the last mentioned means, and conductive connections connecting said-electromagnetic means in said circuit closed by said parallel circuit closers.

Noreferences cited. 

